What is Database?

A database is a structured collection of records or data that is stored in a computer system. 

Database is not the must have component for building a web site.  Database is used to store different type of data in the system and the data can be easily reused by any page of the web site. Special knowledge is requred to access data in the database.

Database is used by almost all popular web related software, like blog, forum, shopping cart, web store, online photo gallery, etc.

Most web hosting provider provide MySQL and PostgreSQL for Linux plan, and MSSQL for Windows plan.